Playboy art dealer Helly Nahmad went to jail last week for his involvement in a $100 million international gambling ring that sources said drew A-listers like Leonardo DiCaprio and Alex Rodriguez — but not before a monthlong, pre-prison party, says a source.

The spy tells us the send-off to good times ended with a last supper of sorts, a West Village dinner with friends including magician David Blaine a few days ago.

While not his $21.7 million Trump Tower condo, where he held the illegal games, the son of billionaire art dealer David Nahmad is starting to serve out his one-year-and-one-day sentence at the cushy Otisville, NY, Federal Correctional Institution, according to our source, where Ponzi schemer Kenneth Starr (not the one of Clinton/Lewinsky fame) is doing time.

Nahmad’s lawyer, Benjamin Brafman, didn’t get back to us.

The high-stakes ring reportedly was led by Russian gangster Alimzhan Tokhtakhounov, who tried to fix 2002 Olympic skating competitions.